程序包 cn.taketoday.core

类 OverridingClassLoader

java.lang.Object

java.lang.ClassLoader

cn.taketoday.core.DecoratingClassLoader

cn.taketoday.core.OverridingClassLoader

public class OverridingClassLoader
extends DecoratingClassLoader

ClassLoader that does not always delegate to the parent loader as normal class loaders do. This enables, for example, instrumentation to be forced in the overriding ClassLoader, or a "throwaway" class loading behavior where selected application classes are temporarily loaded in the overriding ClassLoader for introspection purposes before eventually loading an instrumented version of the class in the given parent ClassLoader.

从以下版本开始:

4.0

作者:

Rod Johnson, Juergen Hoeller, TODAY 2021/9/11 12:14

字段概要

字段

修饰符和类型	字段	说明
static final String[]	DEFAULT_EXCLUDED_PACKAGES	Packages that are excluded by default.

构造器概要

构造器

构造器	说明
OverridingClassLoader(ClassLoader parent)	Create a new OverridingClassLoader for the given ClassLoader.
OverridingClassLoader(ClassLoader parent, ClassLoader overrideDelegate)	Create a new OverridingClassLoader for the given ClassLoader.

方法概要

修饰符和类型	方法	说明
protected boolean	isEligibleForOverriding(String className)	Determine whether the specified class is eligible for overriding by this class loader.
protected byte[]	loadBytesForClass(String name)	Load the defining bytes for the given class, to be turned into a Class object through a ClassLoader.defineClass(byte[], int, int) call.
Class<?>	loadClass(String name)
protected Class<?>	loadClass(String name, boolean resolve)
protected Class<?>	loadClassForOverriding(String name)	Load the specified class for overriding purposes in this ClassLoader.
protected InputStream	openStreamForClass(String name)	Open an InputStream for the specified class.
protected byte[]	transformIfNecessary(String name, byte[] bytes)	Transformation hook to be implemented by subclasses.

从类继承的方法 cn.taketoday.core.DecoratingClassLoader

excludeClass, excludePackage, isExcluded

从类继承的方法 java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findClass, findLibrary, findLoadedClass, findResource, findResource, findResources, findSystemClass, getClassLoadingLock, getDefinedPackage, getDefinedPackages, getName, getPackage, getPackages, getParent, getPlatformClassLoader, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, getUnnamedModule, isRegisteredAsParallelCapable, registerAsParallelCapable, resolveClass, resources, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

DEFAULT_EXCLUDED_PACKAGES

public static final String[] DEFAULT_EXCLUDED_PACKAGES

Packages that are excluded by default.

构造器详细资料

OverridingClassLoader

public OverridingClassLoader(@Nullable
 ClassLoader parent)

Create a new OverridingClassLoader for the given ClassLoader.

参数:

parent - the ClassLoader to build an overriding ClassLoader for

OverridingClassLoader

public OverridingClassLoader(@Nullable
 ClassLoader parent,
 @Nullable
 ClassLoader overrideDelegate)

Create a new OverridingClassLoader for the given ClassLoader.

参数:

parent - the ClassLoader to build an overriding ClassLoader for

overrideDelegate - the ClassLoader to delegate to for overriding

从以下版本开始:

4.0

方法详细资料

loadClass

public Class<?> loadClass(String name)
                   throws ClassNotFoundException

覆盖:

loadClass 在类中 ClassLoader

抛出:

ClassNotFoundException

loadClass

protected Class<?> loadClass(String name,
 boolean resolve)
                      throws ClassNotFoundException

覆盖:

loadClass 在类中 ClassLoader

抛出:

ClassNotFoundException

isEligibleForOverriding

protected boolean isEligibleForOverriding(String className)

Determine whether the specified class is eligible for overriding by this class loader.

参数:

className - the class name to check

返回:

whether the specified class is eligible

另请参阅:

• DecoratingClassLoader.isExcluded(java.lang.String)

loadClassForOverriding

@Nullable
protected Class<?> loadClassForOverriding(String name)
                                   throws ClassNotFoundException

Load the specified class for overriding purposes in this ClassLoader.

The default implementation delegates to ClassLoader.findLoadedClass(java.lang.String), loadBytesForClass(java.lang.String) and ClassLoader.defineClass(byte[], int, int).

参数:

name - the name of the class

返回:

the Class object, or null if no class defined for that name

抛出:

ClassNotFoundException - if the class for the given name couldn't be loaded

loadBytesForClass

@Nullable
protected byte[] loadBytesForClass(String name)
                            throws ClassNotFoundException

Load the defining bytes for the given class, to be turned into a Class object through a ClassLoader.defineClass(byte[], int, int) call.

The default implementation delegates to openStreamForClass(java.lang.String) and transformIfNecessary(java.lang.String, byte[]).

参数:

name - the name of the class

返回:

the byte content (with transformers already applied), or null if no class defined for that name

抛出:

ClassNotFoundException - if the class for the given name couldn't be loaded

openStreamForClass

@Nullable
protected InputStream openStreamForClass(String name)

Open an InputStream for the specified class.

The default implementation loads a standard class file through the parent ClassLoader's getResourceAsStream method.

参数:

name - the name of the class

返回:

the InputStream containing the byte code for the specified class

transformIfNecessary

protected byte[] transformIfNecessary(String name,
 byte[] bytes)

Transformation hook to be implemented by subclasses.

The default implementation simply returns the given bytes as-is.

参数:

name - the fully-qualified name of the class being transformed

bytes - the raw bytes of the class

返回:

the transformed bytes (never null; same as the input bytes if the transformation produced no changes)